<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        .box1{
            width: 300px ;
            height: 200px;
            border: 1px solid red;
            margin-top: 50px;
            display: none;
            position: absolute;
            background-color: brown;

        }
        .conten{
            width: 200px ;
            height: 100px;
            border: 1px solid blue;
            background-color: aqua;
            position: relative;
            margin: 100px;
            
        }
        .conten:hover .box1{
           left: 200px;
            display: block;
            opacity: 0.3;
        }
        .demo{
            bottom: 50px;
            width: 200px;
            height: 100px;
            position: fixed;
            right: 0px;
            background-color: blueviolet;
        }

    </style>
</head>
<body>
    <div style="height:2000px"></div>
    <div class="conten">
        我的菜单
        <div class="box1">
           
        </div>       
    </div>
    12414
    <div class="demo">
        TOP
    </div>
    
</body>
</html>